ref: 8723be0d01ab4150ed6ca63649a6ec1ddcc06efb
dir: /r_draw.c/
/*
Copyright (C) 1996-1997 Id Software, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
// r_draw.c
#include "quakedef.h"
#include "r_local.h"
#include "d_local.h" // FIXME: shouldn't need to include this
#define MAXLEFTCLIPEDGES 100
// !!! if these are changed, they must be changed in asm_draw.h too !!!
#define FULLY_CLIPPED_CACHED 0x80000000
#define FRAMECOUNT_MASK 0x7FFFFFFF
unsigned int cacheoffset;
int c_faceclip; // number of faces clipped
zpointdesc_t r_zpointdesc;
polydesc_t r_polydesc;
clipplane_t *entity_clipplanes;
clipplane_t view_clipplanes[4];
clipplane_t world_clipplanes[16];
medge_t *r_pedge;
qboolean r_leftclipped, r_rightclipped;
static qboolean makeleftedge, makerightedge;
qboolean r_nearzionly;
int sintable[SIN_BUFFER_SIZE];
int intsintable[SIN_BUFFER_SIZE];
mvertex_t r_leftenter, r_leftexit;
mvertex_t r_rightenter, r_rightexit;
typedef struct
{
float u,v;
int ceilv;
} evert_t;
int r_emitted;
float r_nearzi;
float r_u1, r_v1, r_lzi1;
int r_ceilv1;
qboolean r_lastvertvalid;
#if !id386
/*
================
R_EmitEdge
================
*/
void R_EmitEdge (mvertex_t *pv0, mvertex_t *pv1)
{
edge_t *edge, *pcheck;
int u_check;
float u, u_step;
vec3_t local, transformed;
float *world;
int v, v2, ceilv0;
float scale, lzi0, u0, v0;
int side;
if (r_lastvertvalid)
{
u0 = r_u1;
v0 = r_v1;
lzi0 = r_lzi1;
ceilv0 = r_ceilv1;
}
else
{
world = &pv0->position[0];
// transform and project
VectorSubtract (world, modelorg, local);
TransformVector (local, transformed);
if (transformed[2] < NEAR_CLIP)
transformed[2] = NEAR_CLIP;
lzi0 = 1.0 / transformed[2];
// FIXME: build x/yscale into transform?
scale = xscale * lzi0;
u0 = (xcenter + scale*transformed[0]);
if (u0 < r_refdef.fvrectx_adj)
u0 = r_refdef.fvrectx_adj;
if (u0 > r_refdef.fvrectright_adj)
u0 = r_refdef.fvrectright_adj;
scale = yscale * lzi0;
v0 = (ycenter - scale*transformed[1]);
if (v0 < r_refdef.fvrecty_adj)
v0 = r_refdef.fvrecty_adj;
if (v0 > r_refdef.fvrectbottom_adj)
v0 = r_refdef.fvrectbottom_adj;
ceilv0 = (int) ceil(v0);
}
world = &pv1->position[0];
// transform and project
VectorSubtract (world, modelorg, local);
TransformVector (local, transformed);
if (transformed[2] < NEAR_CLIP)
transformed[2] = NEAR_CLIP;
r_lzi1 = 1.0 / transformed[2];
scale = xscale * r_lzi1;
r_u1 = (xcenter + scale*transformed[0]);
if (r_u1 < r_refdef.fvrectx_adj)
r_u1 = r_refdef.fvrectx_adj;
if (r_u1 > r_refdef.fvrectright_adj)
r_u1 = r_refdef.fvrectright_adj;
scale = yscale * r_lzi1;
r_v1 = (ycenter - scale*transformed[1]);
if (r_v1 < r_refdef.fvrecty_adj)
r_v1 = r_refdef.fvrecty_adj;
if (r_v1 > r_refdef.fvrectbottom_adj)
r_v1 = r_refdef.fvrectbottom_adj;
if (r_lzi1 > lzi0)
lzi0 = r_lzi1;
if (lzi0 > r_nearzi) // for mipmap finding
r_nearzi = lzi0;
// for right edges, all we want is the effect on 1/z
if (r_nearzionly)
return;
r_emitted = 1;
r_ceilv1 = (int) ceil(r_v1);
// create the edge
if (ceilv0 == r_ceilv1)
{
// we cache unclipped horizontal edges as fully clipped
if (cacheoffset != 0x7FFFFFFF)
{
cacheoffset = FULLY_CLIPPED_CACHED |
(r_framecount & FRAMECOUNT_MASK);
}
return; // horizontal edge
}
side = ceilv0 > r_ceilv1;
edge = edge_p++;
edge->owner = r_pedge;
edge->nearzi = lzi0;
if (side == 0)
{
// trailing edge (go from p1 to p2)
v = ceilv0;
v2 = r_ceilv1 - 1;
edge->surfs[0] = surface_p - surfaces;
edge->surfs[1] = 0;
u_step = ((r_u1 - u0) / (r_v1 - v0));
u = u0 + ((float)v - v0) * u_step;
}
else
{
// leading edge (go from p2 to p1)
v2 = ceilv0 - 1;
v = r_ceilv1;
edge->surfs[0] = 0;
edge->surfs[1] = surface_p - surfaces;
u_step = ((u0 - r_u1) / (v0 - r_v1));
u = r_u1 + ((float)v - r_v1) * u_step;
}
edge->u_step = u_step*0x100000;
edge->u = u*0x100000 + 0xFFFFF;
// we need to do this to avoid stepping off the edges if a very nearly
// horizontal edge is less than epsilon above a scan, and numeric error causes
// it to incorrectly extend to the scan, and the extension of the line goes off
// the edge of the screen
// FIXME: is this actually needed?
if (edge->u < r_refdef.vrect_x_adj_shift20)
edge->u = r_refdef.vrect_x_adj_shift20;
if (edge->u > r_refdef.vrectright_adj_shift20)
edge->u = r_refdef.vrectright_adj_shift20;
//
// sort the edge in normally
//
u_check = edge->u;
if (edge->surfs[0])
u_check++; // sort trailers after leaders
if (!newedges[v] || newedges[v]->u >= u_check)
{
edge->next = newedges[v];
newedges[v] = edge;
}
else
{
pcheck = newedges[v];
while (pcheck->next && pcheck->next->u < u_check)
pcheck = pcheck->next;
edge->next = pcheck->next;
pcheck->next = edge;
}
edge->nextremove = removeedges[v2];
removeedges[v2] = edge;
}
/*
================
R_ClipEdge
================
*/
void R_ClipEdge (mvertex_t *pv0, mvertex_t *pv1, clipplane_t *clip)
{
float d0, d1, f;
mvertex_t clipvert;
if (clip)
{
do
{
d0 = DotProduct (pv0->position, clip->normal) - clip->dist;
d1 = DotProduct (pv1->position, clip->normal) - clip->dist;
if (d0 >= 0)
{
// point 0 is unclipped
if (d1 >= 0)
{
// both points are unclipped
continue;
}
// only point 1 is clipped
// we don't cache clipped edges
cacheoffset = 0x7FFFFFFF;
f = d0 / (d0 - d1);
clipvert.position[0] = pv0->position[0] +
f * (pv1->position[0] - pv0->position[0]);
clipvert.position[1] = pv0->position[1] +
f * (pv1->position[1] - pv0->position[1]);
clipvert.position[2] = pv0->position[2] +
f * (pv1->position[2] - pv0->position[2]);
if (clip->leftedge)
{
r_leftclipped = true;
r_leftexit = clipvert;
}
else if (clip->rightedge)
{
r_rightclipped = true;
r_rightexit = clipvert;
}
R_ClipEdge (pv0, &clipvert, clip->next);
return;
}
else
{
// point 0 is clipped
if (d1 < 0)
{
// both points are clipped
// we do cache fully clipped edges
if (!r_leftclipped)
cacheoffset = FULLY_CLIPPED_CACHED |
(r_framecount & FRAMECOUNT_MASK);
return;
}
// only point 0 is clipped
r_lastvertvalid = false;
// we don't cache partially clipped edges
cacheoffset = 0x7FFFFFFF;
f = d0 / (d0 - d1);
clipvert.position[0] = pv0->position[0] +
f * (pv1->position[0] - pv0->position[0]);
clipvert.position[1] = pv0->position[1] +
f * (pv1->position[1] - pv0->position[1]);
clipvert.position[2] = pv0->position[2] +
f * (pv1->position[2] - pv0->position[2]);
if (clip->leftedge)
{
r_leftclipped = true;
r_leftenter = clipvert;
}
else if (clip->rightedge)
{
r_rightclipped = true;
r_rightenter = clipvert;
}
R_ClipEdge (&clipvert, pv1, clip->next);
return;
}
} while ((clip = clip->next) != NULL);
}
// add the edge
R_EmitEdge (pv0, pv1);
}
#endif // !id386
/*
================
R_EmitCachedEdge
================
*/
void R_EmitCachedEdge (void)
{
edge_t *pedge_t;
pedge_t = (edge_t *)((unsigned long)r_edges + r_pedge->cachededgeoffset);
if (!pedge_t->surfs[0])
pedge_t->surfs[0] = surface_p - surfaces;
else
pedge_t->surfs[1] = surface_p - surfaces;
if (pedge_t->nearzi > r_nearzi) // for mipmap finding
r_nearzi = pedge_t->nearzi;
r_emitted = 1;
}
/*
================
R_RenderFace
================
*/
void R_RenderFace (msurface_t *fa, int clipflags)
{
int i, lindex;
unsigned mask;
mplane_t *pplane;
float distinv;
vec3_t p_normal;
medge_t *pedges, tedge;
clipplane_t *pclip;
// skip out if no more surfs
if ((surface_p) >= surf_max)
{
r_outofsurfaces++;
return;
}
// ditto if not enough edges left, or switch to auxedges if possible
if ((edge_p + fa->numedges + 4) >= edge_max)
{
r_outofedges += fa->numedges;
return;
}
c_faceclip++;
// set up clip planes
pclip = NULL;
for (i=3, mask = 0x08 ; i>=0 ; i--, mask >>= 1)
{
if (clipflags & mask)
{
view_clipplanes[i].next = pclip;
pclip = &view_clipplanes[i];
}
}
// push the edges through
r_emitted = 0;
r_nearzi = 0;
r_nearzionly = false;
makeleftedge = makerightedge = false;
pedges = currententity->model->edges;
r_lastvertvalid = false;
for (i=0 ; i<fa->numedges ; i++)
{
lindex = currententity->model->surfedges[fa->firstedge + i];
if (lindex > 0)
{
r_pedge = &pedges[lindex];
// if the edge is cached, we can just reuse the edge
if (!insubmodel)
{
if (r_pedge->cachededgeoffset & FULLY_CLIPPED_CACHED)
{
if ((r_pedge->cachededgeoffset & FRAMECOUNT_MASK) ==
r_framecount)
{
r_lastvertvalid = false;
continue;
}
}
else
{
if ((((unsigned long)edge_p - (unsigned long)r_edges) >
r_pedge->cachededgeoffset) &&
(((edge_t *)((unsigned long)r_edges +
r_pedge->cachededgeoffset))->owner == r_pedge))
{
R_EmitCachedEdge ();
r_lastvertvalid = false;
continue;
}
}
}
// assume it's cacheable
cacheoffset = (byte *)edge_p - (byte *)r_edges;
r_leftclipped = r_rightclipped = false;
R_ClipEdge (&r_pcurrentvertbase[r_pedge->v[0]],
&r_pcurrentvertbase[r_pedge->v[1]],
pclip);
r_pedge->cachededgeoffset = cacheoffset;
if (r_leftclipped)
makeleftedge = true;
if (r_rightclipped)
makerightedge = true;
r_lastvertvalid = true;
}
else
{
lindex = -lindex;
r_pedge = &pedges[lindex];
// if the edge is cached, we can just reuse the edge
if (!insubmodel)
{
if (r_pedge->cachededgeoffset & FULLY_CLIPPED_CACHED)
{
if ((r_pedge->cachededgeoffset & FRAMECOUNT_MASK) ==
r_framecount)
{
r_lastvertvalid = false;
continue;
}
}
else
{
// it's cached if the cached edge is valid and is owned
// by this medge_t
if ((((unsigned long)edge_p - (unsigned long)r_edges) >
r_pedge->cachededgeoffset) &&
(((edge_t *)((unsigned long)r_edges +
r_pedge->cachededgeoffset))->owner == r_pedge))
{
R_EmitCachedEdge ();
r_lastvertvalid = false;
continue;
}
}
}
// assume it's cacheable
cacheoffset = (byte *)edge_p - (byte *)r_edges;
r_leftclipped = r_rightclipped = false;
R_ClipEdge (&r_pcurrentvertbase[r_pedge->v[1]],
&r_pcurrentvertbase[r_pedge->v[0]],
pclip);
r_pedge->cachededgeoffset = cacheoffset;
if (r_leftclipped)
makeleftedge = true;
if (r_rightclipped)
makerightedge = true;
r_lastvertvalid = true;
}
}
// if there was a clip off the left edge, add that edge too
// FIXME: faster to do in screen space?
// FIXME: share clipped edges?
if (makeleftedge)
{
r_pedge = &tedge;
r_lastvertvalid = false;
R_ClipEdge (&r_leftexit, &r_leftenter, pclip->next);
}
// if there was a clip off the right edge, get the right r_nearzi
if (makerightedge)
{
r_pedge = &tedge;
r_lastvertvalid = false;
r_nearzionly = true;
R_ClipEdge (&r_rightexit, &r_rightenter, view_clipplanes[1].next);
}
// if no edges made it out, return without posting the surface
if (!r_emitted)
return;
r_polycount++;
surface_p->data = (void *)fa;
surface_p->nearzi = r_nearzi;
surface_p->flags = fa->flags;
surface_p->insubmodel = insubmodel;
surface_p->spanstate = 0;
surface_p->entity = currententity;
surface_p->key = r_currentkey++;
surface_p->spans = NULL;
pplane = fa->plane;
// FIXME: cache this?
TransformVector (pplane->normal, p_normal);
// FIXME: cache this?
distinv = 1.0 / (pplane->dist - DotProduct (modelorg, pplane->normal));
surface_p->d_zistepu = p_normal[0] * xscaleinv * distinv;
surface_p->d_zistepv = -p_normal[1] * yscaleinv * distinv;
surface_p->d_ziorigin = p_normal[2] * distinv -
xcenter * surface_p->d_zistepu -
ycenter * surface_p->d_zistepv;
//JDC VectorCopy (r_worldmodelorg, surface_p->modelorg);
surface_p++;
}
/*
================
R_RenderBmodelFace
================
*/
void R_RenderBmodelFace (bedge_t *pedges, msurface_t *psurf)
{
int i;
unsigned mask;
mplane_t *pplane;
float distinv;
vec3_t p_normal;
medge_t tedge;
clipplane_t *pclip;
// skip out if no more surfs
if (surface_p >= surf_max)
{
r_outofsurfaces++;
return;
}
// ditto if not enough edges left, or switch to auxedges if possible
if ((edge_p + psurf->numedges + 4) >= edge_max)
{
r_outofedges += psurf->numedges;
return;
}
c_faceclip++;
// this is a dummy to give the caching mechanism someplace to write to
r_pedge = &tedge;
// set up clip planes
pclip = NULL;
for (i=3, mask = 0x08 ; i>=0 ; i--, mask >>= 1)
{
if (r_clipflags & mask)
{
view_clipplanes[i].next = pclip;
pclip = &view_clipplanes[i];
}
}
// push the edges through
r_emitted = 0;
r_nearzi = 0;
r_nearzionly = false;
makeleftedge = makerightedge = false;
// FIXME: keep clipped bmodel edges in clockwise order so last vertex caching
// can be used?
r_lastvertvalid = false;
for ( ; pedges ; pedges = pedges->pnext)
{
r_leftclipped = r_rightclipped = false;
R_ClipEdge (pedges->v[0], pedges->v[1], pclip);
if (r_leftclipped)
makeleftedge = true;
if (r_rightclipped)
makerightedge = true;
}
// if there was a clip off the left edge, add that edge too
// FIXME: faster to do in screen space?
// FIXME: share clipped edges?
if (makeleftedge)
{
r_pedge = &tedge;
R_ClipEdge (&r_leftexit, &r_leftenter, pclip->next);
}
// if there was a clip off the right edge, get the right r_nearzi
if (makerightedge)
{
r_pedge = &tedge;
r_nearzionly = true;
R_ClipEdge (&r_rightexit, &r_rightenter, view_clipplanes[1].next);
}
// if no edges made it out, return without posting the surface
if (!r_emitted)
return;
r_polycount++;
surface_p->data = (void *)psurf;
surface_p->nearzi = r_nearzi;
surface_p->flags = psurf->flags;
surface_p->insubmodel = true;
surface_p->spanstate = 0;
surface_p->entity = currententity;
surface_p->key = r_currentbkey;
surface_p->spans = NULL;
pplane = psurf->plane;
// FIXME: cache this?
TransformVector (pplane->normal, p_normal);
// FIXME: cache this?
distinv = 1.0 / (pplane->dist - DotProduct (modelorg, pplane->normal));
surface_p->d_zistepu = p_normal[0] * xscaleinv * distinv;
surface_p->d_zistepv = -p_normal[1] * yscaleinv * distinv;
surface_p->d_ziorigin = p_normal[2] * distinv -
xcenter * surface_p->d_zistepu -
ycenter * surface_p->d_zistepv;
//JDC VectorCopy (r_worldmodelorg, surface_p->modelorg);
surface_p++;
}
/*
================
R_RenderPoly
================
*/
void R_RenderPoly (msurface_t *fa, int clipflags)
{
int i, lindex, lnumverts, s_axis, t_axis;
float dist, lastdist, lzi, scale, u, v, frac;
unsigned mask;
vec3_t local, transformed;
clipplane_t *pclip;
medge_t *pedges;
mplane_t *pplane;
mvertex_t verts[2][100]; //FIXME: do real number
polyvert_t pverts[100]; //FIXME: do real number, safely
int vertpage, newverts, newpage, lastvert;
qboolean visible;
// FIXME: clean this up and make it faster
// FIXME: guard against running out of vertices
s_axis = t_axis = 0; // keep compiler happy
// set up clip planes
pclip = NULL;
for (i=3, mask = 0x08 ; i>=0 ; i--, mask >>= 1)
{
if (clipflags & mask)
{
view_clipplanes[i].next = pclip;
pclip = &view_clipplanes[i];
}
}
// reconstruct the polygon
// FIXME: these should be precalculated and loaded off disk
pedges = currententity->model->edges;
lnumverts = fa->numedges;
vertpage = 0;
for (i=0 ; i<lnumverts ; i++)
{
lindex = currententity->model->surfedges[fa->firstedge + i];
if (lindex > 0)
{
r_pedge = &pedges[lindex];
verts[0][i] = r_pcurrentvertbase[r_pedge->v[0]];
}
else
{
r_pedge = &pedges[-lindex];
verts[0][i] = r_pcurrentvertbase[r_pedge->v[1]];
}
}
// clip the polygon, done if not visible
while (pclip)
{
lastvert = lnumverts - 1;
lastdist = DotProduct (verts[vertpage][lastvert].position,
pclip->normal) - pclip->dist;
visible = false;
newverts = 0;
newpage = vertpage ^ 1;
for (i=0 ; i<lnumverts ; i++)
{
dist = DotProduct (verts[vertpage][i].position, pclip->normal) -
pclip->dist;
if ((lastdist > 0) != (dist > 0))
{
frac = dist / (dist - lastdist);
verts[newpage][newverts].position[0] =
verts[vertpage][i].position[0] +
((verts[vertpage][lastvert].position[0] -
verts[vertpage][i].position[0]) * frac);
verts[newpage][newverts].position[1] =
verts[vertpage][i].position[1] +
((verts[vertpage][lastvert].position[1] -
verts[vertpage][i].position[1]) * frac);
verts[newpage][newverts].position[2] =
verts[vertpage][i].position[2] +
((verts[vertpage][lastvert].position[2] -
verts[vertpage][i].position[2]) * frac);
newverts++;
}
if (dist >= 0)
{
verts[newpage][newverts] = verts[vertpage][i];
newverts++;
visible = true;
}
lastvert = i;
lastdist = dist;
}
if (!visible || (newverts < 3))
return;
lnumverts = newverts;
vertpage ^= 1;
pclip = pclip->next;
}
// transform and project, remembering the z values at the vertices and
// r_nearzi, and extract the s and t coordinates at the vertices
pplane = fa->plane;
switch (pplane->type)
{
case PLANE_X:
case PLANE_ANYX:
s_axis = 1;
t_axis = 2;
break;
case PLANE_Y:
case PLANE_ANYY:
s_axis = 0;
t_axis = 2;
break;
case PLANE_Z:
case PLANE_ANYZ:
s_axis = 0;
t_axis = 1;
break;
}
r_nearzi = 0;
for (i=0 ; i<lnumverts ; i++)
{
// transform and project
VectorSubtract (verts[vertpage][i].position, modelorg, local);
TransformVector (local, transformed);
if (transformed[2] < NEAR_CLIP)
transformed[2] = NEAR_CLIP;
lzi = 1.0 / transformed[2];
if (lzi > r_nearzi) // for mipmap finding
r_nearzi = lzi;
// FIXME: build x/yscale into transform?
scale = xscale * lzi;
u = (xcenter + scale*transformed[0]);
if (u < r_refdef.fvrectx_adj)
u = r_refdef.fvrectx_adj;
if (u > r_refdef.fvrectright_adj)
u = r_refdef.fvrectright_adj;
scale = yscale * lzi;
v = (ycenter - scale*transformed[1]);
if (v < r_refdef.fvrecty_adj)
v = r_refdef.fvrecty_adj;
if (v > r_refdef.fvrectbottom_adj)
v = r_refdef.fvrectbottom_adj;
pverts[i].u = u;
pverts[i].v = v;
pverts[i].zi = lzi;
pverts[i].s = verts[vertpage][i].position[s_axis];
pverts[i].t = verts[vertpage][i].position[t_axis];
}
// build the polygon descriptor, including fa, r_nearzi, and u, v, s, t, and z
// for each vertex
r_polydesc.numverts = lnumverts;
r_polydesc.nearzi = r_nearzi;
r_polydesc.pcurrentface = fa;
r_polydesc.pverts = pverts;
// draw the polygon
D_DrawPoly ();
}
/*
================
R_ZDrawSubmodelPolys
================
*/
void R_ZDrawSubmodelPolys (model_t *pmodel)
{
int i, numsurfaces;
msurface_t *psurf;
float dot;
mplane_t *pplane;
psurf = &pmodel->surfaces[pmodel->firstmodelsurface];
numsurfaces = pmodel->nummodelsurfaces;
for (i=0 ; i<numsurfaces ; i++, psurf++)
{
// find which side of the node we are on
pplane = psurf->plane;
dot = DotProduct (modelorg, pplane->normal) - pplane->dist;
// draw the polygon
if (((psurf->flags & SURF_PLANEBACK) && (dot < -BACKFACE_EPSILON)) ||
(!(psurf->flags & SURF_PLANEBACK) && (dot > BACKFACE_EPSILON)))
{
// FIXME: use bounding-box-based frustum clipping info?
R_RenderPoly (psurf, 15);
}
}
}